There are many factors which militate in favor of aqueous dispersions. Among these are increased awareness of the environmental hazards associated with organic solvent vapors entering the atmosphere, the desirability of a single system that can be applied not only by the more conventional techniques of spray or roller coating but also by electrodeposition, and the economy resulting from the substitution of water for some or all of the solvents in a coating composition.
Aqueous dispersions of perfluoroolefin polymers containing film-forming materials are known, as evidenced by U.S. Pat. No. 4,087,394 issued May 2, 1978 to Concannon. The cured films obtained from such dispersions offer such advantages as excellent release properties, high lubricity, high resistance to heat and chemicals, and good electrical insulating properties.
The present invention, however, offers improvements by virtue of its utilization of a unique water-borne film former based on the reaction product of a carboxyl-functional polymer, an epoxide, and a tertiary amine.
This type of film-former is described in U.S. Pat. No. 4,247,439 issued Jan. 27, 1981 to Matthews and Sommerfeld.